July 16, 1917 Movement and Distribution of Moisture in Soil 



129 



sented the averages of the 10 samplings for each of the first 6 feet through- 

 out the season of 1916. Each column is the average of 240 samples. 



The 4-inch straw mulch on the fall-plowed land prevented moisture loss 

 better than other treatments, while the plot that was not plowed but had 

 the weeds pulled was next in eflficiency. Disking fall-plowed land once in 

 the spring and cultivating spring-plowed land 6 inches deep proved to be 

 the best cultural methods under fall and spring plowing, respectively. 



The efficiency of spring-plowed plots in moisture conservation in- 

 creased with the increased depth of cultivation, while in the fall-plowed 

 plots the reverse is indicated. Since even the uncultivated soils main- 

 tained an average moisture content of about 19 per cent throughout the 

 season, the importance of cultivation on land kept free from weeds was 

 not so great for this year as might have been expected. 



Percentage of moisture 



S. $ 7 ^ 9 /p // /2 /^ /f- 



/7 /(f /? 2p 



>^^^^^m^M:cum:aW^^^},^^^\pm^ 



^^m^^^^^^ ^;r;ch ' 'cuih.afwn. m^^^^^m^^^m^^^m^^ 



^:^^^^^^^^^^^ rinc)^ ^'cuLfimbpn:^^^^^^^^^^^^^^^^^^ 



f-/nch cuL tr/G fio n I 



Jubso/led ly- cuLTii'ated 1/-" 

 DiAced once m sprina X 



m^m^:^m^Nof "pL^y.ed since '-:J9IV-yxc¥d5 "~pjLLid}-M 

 i=-/nrh 5?rciv rculch 



•Spring pLoived 



fail plowed 



Nof plowed 



Fig. 1 1 .—Diagram showing the effect of cultural methods under dry-farming conditions on theav erage 

 final content of moisture in the soil to a depth of 6 feet. Each column is an average of 240 samplings. 



CuLTURAt Experiments at Nephi Between 1909 and 1916 



This cultural experiment at the Nephi Substation was conducted dur- 

 ing the eight years from 1909 to 191 6, inclusive. All spring- and all fall- 

 plowed fallow plots were sampled in duolicate to a depth of 6 feet in the 

 spring, the summer, and the fall. 



From figure 1 2 a rather pronounced difference is seen between the dis- 

 tribution in the fall- and spring-plowed plots. In the former the top foot 

 had the least moisture and the second foot the most, with a decline from 

 this to the fifth foot. ■ The spring-plowed plots, on the other hand, showed 

 an increase downward from the surface to the fourth foot before the de- 

 cHne began. Except in the first and second feet in the spring, the spring- 

 plowed plots had more moisture than the fall-plowed ones. This differ- 

 ence in favor of spring plo^ving was most marked in the third, fourth, and 

 fifth feet. It would seem from this that fall-plowed soils tend to hold 



